When
we were in grade school, many of us learned that there were
four basic tastes: sweet, sour, salty and bitter. Now there's
a new taste to learn and it's called umami (pronounced "oo-mommy").
Actually, while the term is new to us, it's not new to the Japanese,
who have used the term to describe the "fifth taste"
since the early 1900s. What exactly is the umami taste? Well,
there's no English word that's synonymous with umami, however
it's most often described as a "savory" or "meaty"
taste.

Being
able to distinguish the umami taste takes some practice because
it's not as obvious as other tastes, such as sweet or bitter.
For example, when tasting a homemade chicken broth made without
salt or seasoning of any kind, you may find it bland and practically
tasteless. If you added a small amount of monosodium glutamate
to that same broth, the umami taste it provides may lead you
to describe the "enhanced" broth as tasting "more
like chicken" than the first broth. This taste is not as
simple as making something taste more salty (salt alone can
do that). Rather, the umami taste is one of richness, fullness
and complexity. Simply put, it just makes the food taste more
delicious.

Glutamate's
the keyThe
amino acid glutamate could well be called "nature's flavor
enhancer" because it conveys the umami taste in foods.
Glutamate is also well known among food and nutrition professionals
as one of the most common "building blocks" of protein.
As such, it's no surprise that most foods contain some amount
of glutamate. Protein foods, such as meat, fish, cheese, milk
and some vegetables are especially good sources of glutamate.
Not coincidentally, these foods also have a lot of umami taste.

In
some foods, the amount of glutamate they containand their
flavorincreases as they age or ripen. For example, according
to research, aged ham and aged cheese have much more glutamate
than their "younger" counterparts. The graphic to
the left illustrates this concept using a ripening tomato. As
a tomato ripens from green to red, its glutamate content increases
dramatically. The superior flavor of the ripe tomato can be
attributed, in part, to its higher glutamate level.

Adding
umami to foods
Over 1,200 years ago, Asian cooks began adding a type of seaweed
found in the Pacific Ocean to their soup stocks. They had discovered
that foods cooked in this seaweed broth simply tasted better.
What these chefs didn't know was that the broth's unique flavor
enhancement quality was due to the high levels of naturally
occurring glutamate in the seaweed.

Finally,
in 1908, the link between glutamate and the seaweed was discovered.
A professor at Tokyo Imperial University, Dr. Kikunae Ikeda,
isolated glutamate from the seaweed and unlocked the secret
of the plant's flavor-enhancing properties. Dr. Ikeda then went
on to study various forms of glutamate, trying to find one that
conveyed the umami taste and was also practical to produce commercially.
He found that the sodium salt form, called monosodium glutamate,
fit the bill: it provided umami and was easy for home cooks
to use and store.

Monosodium
glutamate, often referred to as "MSG", was first produced
in Japan in 1909, and made its U.S. debut in 1917. Since then,
food manufacturers and home cooks alike have used MSG to augment
the flavor of a wide variety of foods.

Recognizing
that "Mother Nature" knows best, when food manufacturers
add monosodium glutamate to foods, they use it in levels that
are comparable to the glutamate levels found in natural foods.
Generally, this means only a small amount is usedusually
between 0.1% and 0.8% of the food's weight. Home cooks have
it easierthere's a "rule of thumb" for how much
MSG to use.

You
might be surprised to learn that, according to a 1995 U.S. Food
and Drug Administration study, some foods naturally contain
higher levels of glutamate than those typically added to foods
during manufacturing. For example, the natural glutamate level
in aged Parmesan cheese was found to be up to 10 times that
found in chicken broth with added monosodium glutamate!